Engine anti-stall device



p 11, 1955 J. scHwElss 2,762,614

ENGINE ANTI-STALL DEVICE Filed March 18, 1952 FIG.6. =0

INVENTOR. JOSEPH SCHWEISS ATTORNEY United States Patent.

ENGINE ANTI-STALL DEVICE Joseph 'Schweiss, St. Louis, Mo., assignor, bymesne assignments, to ACF Industries, Incorporated, New York, N. Y., acorporation of New Jersey I This invention relates to anti-stall devicesfor use with internal combustion engines, particularly, of theautomotive type.

Where the carburetor throttle valve is suddenly returned to its normalidling position, the resultant sharp increase in depression in theengine manifold posterior to the throttle may result in sweeping intothe engine whatever excess fuel may have been deposited in or collectedon the walls of the manifold. The resulting mixture in the firingchambers may be so rich as to cause a stumble or even to stall theengine. Various dash pot devices have been suggested for delaying theclosing of the throttle valve, to avoid this condition, but thesedevices are rather bulky, complicated, and expensive.

It is the principal object of the present invention to provideconsiderably simplified and less expensive means for preventing enginestalling under the conditions above noted. According'to the presentinvention, there is pro- .suctionis established posterior to thethrottle and to open the lay-pass when less than idling suctionprevails. There is also providedme'ans for delaying closing of thebypass, as the throttle returns to idling position, so that thesupplemental air is supplied, momentarily, When there would be,otherwise, the liability of stalling.

In the-accompanying drawing which illustrates the invention:

Fig. 1 is a vertical transverse section through an automotive carburetorembodying the invention.

Fig. 2 is an enlarged section showing the anti-stall valve in its closedposition.

Fig. 3 is a view similar to Fig. 2, but showing the antistall valveopened.

Figs. 4, 5 and 6 are detail sectional views showing a modifiedanti-stall valve mounted in the wall of the carburetor or intakemanifold instead of upon the carburetor throttle valve and showing thevalve in three different positions.

The carburetor in Fig. 1 has a downdraft mixture conduit 8 with a flange9 at its lower, outlet extremity for at tachment to the intake manifold(not shown). The discharge of fuel and air mixture is controlled, in theusual manner, by a throttle valve disk 10 which is connected by suitablelinkage to the accelerator pedal. Adjacent the mixture conduit is aconstant level fuel bowl 11 enclosing a float 12 and, in its lowerportion, a main metering orifice element 13 through which fuel issupplied to upwardly inclined, main fuel passage 14. The main fuelpassage discharges through a nozzle 15 into the smallest of a series ofventuri tubes 16. A choke valve 17 in the inlet horn 18 of thecarburetor mixture conduit provides for reducing the supply of air formixture with fuel issuing from main nozzle 15, in starting.

Idling fuel is supplied through a restriction tube 19, communicatingwith main fuel passage 14, and passages 20 connecting with ports 21adjacent the posterior to the edge 2,762,614 Patented Sept. 11, 1956 iceof throttle valve 10, when closed. As is customary, the throttle valve,in closing, is limited to a slightly open position for normal idling inwhich some air passes the edge of the valve disk for mixing with theextra rich mixture which issues from the idling ports. Main orificeelement 13 is controlled by a metering pin 22.

The novel anti-stall device is mounted on the throttle disk and includesa small cylindrical casing 23 with an annularly grooved, upper portion24 secured within a port 25 in the throttle disk, by means of a suitableriveting or peening operation, as at 26. Annularly spaced, inwar-d lips27 provide upper stops for the anti-stall valve. The upper end of thecasing is open to form a port 28 which exposes the interior of the valvecasing to atmospheric conditions on the anterior or upstream side of thethrottle valve. The portion of casing 23 on the downstream or posteriorside of the throttle is provided with a pair of ports 29, in the sidewall thereof, and a port 30 in the lower end wall thereof.

Working in chamber 31 in casing 23 is a slide valve comprising acup-shaped part 32, and intermediate annularly slotted part 33 and acylindrical end part 34. Ports 35 connect the intermediate, recessedpart 33 with the hollow interior 36 in the upper part of the slidevalve. A coil spring 37 is compressed between the ported, bottom wall ofthe casing and the opposed wall of the cup-shaped portion .32 of theslide valve and constantly urges the slide .valve upwardly. Spring 37 iscalibrated, in relation to port 30, so that the slide valve will bedrawn fully inwardly, as in Fig. 2, when exposed to at least normalidling suction through port 39. Port 30 is made quite small so that anappreciable time interval will be required to evacuate the interiorofcup-shaped portion 32 of the slide valve and,

complete an air by-pass through the throttle valve, including opening 28at the top of the valve casing, hollow interior 36 in the upper part ofthe slide valve, valve ports .35, and valve casing ports 29.

In operation, the slide valve will assume'the position .of Fig.2 whenthe engine is operating with the throttle valve in its maximum closed.ornormal idling position so that the slide valve will be exposed,through port 30 to, at least, normal idling suction, while the top ofthe slide valve is exposed to substantially atmospheric pressure. Inthis position, spring 37 is collapsed and cup-shaped portion 32 of theslide valve seats against the bottom wall of casing 23 to limit thedownward movement of the slide valve. Bleed ports 29 in the side of thecasing are cut oil? by cylindrical portion 34 at the upper end of theslide valve. When the throttle valve is opened, reducing the suctionapplied through port 30 to the undersurface of the slide valve, spring37 expands, as in Fig. 3, causing registry of ports 29 and 35, aspreviously explained, and completing the supplemental air by-passthrough the throttle valve. This permits air to pass through thethrottle valve and dilute the mixture. When the throttle valve is open,such dilution is of no consequence. Because of the restricted suctioncommunication at port 30 into the interior of the suction casing, themotion of the slide valve from the position of Fig. 3 to that of Fig. 2,immediately upon closing of the throttle valve, will be slightly delayedso that, for a short period, more air will be supplied to the engine,than would otherwise be the case, which air dilutes the otherwiseexcessively rich fuel mixture. This also somewhat increases the enginespeed, momentarily, so that thetendency to stumble or stall is avoided.

Since the slide valve will be in its open position, of Fig.

.3, at low suction, the supplemental air duct will be open duringstarting which may aid in starting the engine with the throttle valveclosed.

In Figs. 4, 5, and 6, the anti-stall slide valve 40 reciprocates withina casing 41 which is threadedly mounted, as

cate through clearance space 46 with the engine manifold 44. The open,outer extremity 49 of casing 41 communieates with atmosphere. The slidevalve has annularly arranged ports 50 opening into its hollow interior51.

Fig. shows slide valve 40 in an intermediate position in which its ports50 are in registry with casing ports 48 and forming with the same, andwith clearance space 46,

with the hollow interior portion 51 of the slide valve,

and with the open end portion 49 of casing 41, a supplemental airby-pass into the intake manifold.

In this form, coiled spring 52 is calibrated, with relation to suctionport 53 in the end wall of casing 41 to permit the slide valve to bemoved to the extreme inward, fully closed position of Fig. 6 when theslide valve is exposed through port 53 to suction at least equal tonormal idling suction. When the suction to which the slide valve isexposed drops from normal idling suction, the spring 52 expands, movingthe slide valve outwardly, first to the intermediate position of Fig. 5,in which the supplemental air by-pass is opened, then to the closedposition of Fig. 4, with the end of the slide valve seated against avalve stop ring 54 lodged in the end of casing 41. This third positionof the valve, of Fig. 4, is provided so that the supplemental air ductwill be closed during starting and, in fact, at substantially all timesexcept for a short period after the throttle valve is returned to itsnormal idling position, with the engine in operation.

In this form, as well as in the first form, restricted suc- "tion port53 provides for a delayed movement of the slide valve from its normal,closed position of Fig. 4, through the open position of Fig. 5, to theagain closed position of Fig. 6. The rate of movement of the slidevalve, as adjusted by the size of suction port 53 and the strength ofspring 52, and the length of suction ports 48 and 50, provide for theby-pass duct being in efiect for the proper length of time to eliminatethe stalling condition mentioned above, without, at other times,undesirably increasing the normal idle speed of the engine.

The size of the various suction and air bleed parts and the strength ofthe slide valve actuating spring will be adjusted, of course, inaccordance with the conditions which prevail in the particular engineand carburetor at hand. Details of the valve arrangement and positioningmay be modified as Will occur to those skilled in the art and theexclusive use of all modifications as come within the scope of theappended claim is contemplated.

I claim:

An anti-stall device for a carburetor having an induction conduit with athrottle valve, comprising, in combination, a casing forming a chambermounted on said conduit adjacent said throttle valve, a first port insaid casing for exposing said chamber to atmospheric pressure, secondand third ports in said casing for exposing said chamber to pressures onthe downstream side of said throttle, means in said chamber constantlyin communication with said first and second ports and actuable inresponse to differences in pressures produced by engine speed andthrottle position for controlling said third port, including asuctionresponsive valve movable between extreme positions to close saidthird port in response to variations in pressure differential actingthereon and to open said third in intermediate positions, means forretarding the action of said valve in response to variations in pressuredifierential at said first and second ports, a spring biasing said valvein opposition to the eflect of pressure differences, said spring beingcalibrated to shift said valve to one extreme position to closecommunication between said first and third ports in response topressures at said first and second ports when said throttle is open, andto be compressed to close said third port in response to pressuresnormally present at said first and second ports when said throttle isclosed to idle position, whereby throttle movement from open to closedposition opens said valve temporarily to supply supplemental air for ashort period after said throttle is closed.

References Cited in the file of thi patent UNITED STATES PATENTS1,718,644 Gilbert June 25, 1929 1,763,362 Linkert June 10, 19301,944,397 Berry Jan. 23, 1934 2,102,846 Hunt Dec. 21, 1937 I FOREIGNPATENTS' 405,346 Great Britain Feb. 8, 1934

